Summary of the 1996 Portland Cement Concrete Performance-Related Specification Shadow Field Trial: Iowa State Route 23

The results of a “shadow” field trial (actual contractor pay was not affected) conducted to demonstrate a Level 1 prototype performance-related specification (PRS) for jointed plain concrete pavement construction are presented. The Level 1 PRS (the most practical PRS method at this time) is believed to be immediately implementable because it uses currently practiced sampling and testing procedures. The future pavement performance is represented by distress indicators that are predicted on the basis of measured acceptance quality characteristic (AQC) values. Pay factors are determined independently for each AQC from simulated pay factor versus AQC curves and corresponding equations. The overall lot pay factor is determined from a simple mathematical manipulation of the individual AQC pay factors. The specific objectives of the field trial were to verify and confirm the draft specification’s effectiveness, identify potential problem areas, and determine its reasonableness. This paper discusses all aspects of the field trial including the relevant definitions, selection of lots and sublots, sampling and testing plan, calculation of shadow PRS pay adjustments, problems encountered, and a summary of lessons learned.